Migratory flyway and geographical distance are barriers to the gene flow of influenza virus among North American birds - Lam, Tommy; Ip, S.; Ghedin, E.; Wentworth, David; Halpin, Rebecca A.; Stockwell, T.; Dusek, Robert; Bortner, James; Hoskins, Jenny; Bales, Bradley; Yparraguirre, Daniel; Holmes, E. (Ecology Letters, 2012)